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-   -   Dahon Jetstream XP with 2x Shimano Alfine (http://www.bikeforums.net/folding-bikes/344420-dahon-jetstream-xp-2x-shimano-alfine.html)

euhmoins 09-16-07 10:46 PM

Dahon Jetstream XP with 2x Shimano Alfine
 
Hi everyone,

I tried a Dahon Jetstream XP last week and I liked it. The only thing I do not feel confortable with is the SRAM dual drive: apart from the fact that I found it little bit noisy, I really enjoy internal hubs.
I wonder if it is possible to adapt an 8 gears Shimano Alfine (I like shift levers) with two front cranksets on the Jetstream XP.
What do you think of this ? Is it technically possible ? Will I still be able to fold the bike ? Do I wast my time and money with this and should directly go buy a Bike-Friday ?

Thanks,
best regards
Valéry.

jur 09-17-07 12:42 AM

It is possible but only if you are prepared to use manual derailing. There is no front derailer that will fit.

BruceMetras 09-17-07 07:48 AM

Quote:

Originally Posted by euhmoins (Post 5281301)
Hi everyone,

I tried a Dahon Jetstream XP last week and I liked it. The only thing I do not feel confortable with is the SRAM dual drive: apart from the fact that I found it little bit noisy, I really enjoy internal hubs.
I wonder if it is possible to adapt an 8 gears Shimano Alfine (I like shift levers) with two front cranksets on the Jetstream XP.
What do you think of this ? Is it technically possible ? Will I still be able to fold the bike ? Do I wast my time and money with this and should directly go buy a Bike-Friday ?

Thanks,
best regards
Valéry.

Here's what I did to a Jetstream XP well over a year ago.. Built new rear wheel using Alex16 rim and Shimano Nexus 8sp Premium hub.. installed Schlumpf Speed Drive... this bike is running on Avocet 20x1.75 tires which I found to be a great tire for speed and comfort.. overall gear range is just over 500%, about the same as a 11/34 megarange cassette and a 53/32 crank... this bike gets almost daily use and has been totally reliable, folds nicely, and travels well (nothing gets knocked out of alignment).... I love this setup, however, unless you dislike the low hanging derailleur of your present rig, the Dual Drive is a nice piece and should provide years of service ...

http://farm2.static.flickr.com/1265/...4946d307_o.jpg

http://farm2.static.flickr.com/1304/...40b9739c_o.jpg

Loch 09-17-07 09:50 AM

The dual drive (internal gears) should not be any louder than any other internal hub. If it is, it is not adjusted properly or there is something wrong with it. My Dual drive is very quite and I love it.

If you ran an internal rear and dual rings up front you would still need a tensioner. So you would still have something hanging down like a derailluer. I really not sure what you would gain.

I suggest taking another look a the dual drive, it really is quite nice.

Or do what Bruce did, that's pretty sweet.

euhmoins 09-28-07 06:43 AM

Hi all,

First of all, many thanks for your reply.

@Bruce: Congratulation for your bike: a really interesting setup!
I don't know if I like or dislike the low hanging derailleur, I guess I have to try it first to know.

@Loch: Thx for your reply! I have tested the Dual Drive twice and was twice dirsturbed by its noice. I should maybe check up my ears ;)

The situation changed a little since my previous post: I know a little bit more about a few things but still don't know what to buy/build.

I had the opportunity to test a "velotraum": a dahon bike customized made by a german company (A Dahon Vitesse Alu Frame without "low-end" components and with whatever you like ... nexus premium, deore 9 speed, schlumpf speed-drive). I learnt the followings from this experience:
* Those Big-Apples tires are pretty good and represent a good alternative to the "short-range" suspensions of the Jetstream XP (I only fully realized it after having tested them, simply seeing their advantages in written wasn't enough)
* The Vitesse/Speed frame's form (K series Frame) is definitely the one I prefer: sticks to the street, can drive without hands without fear :)

Furthermore, I had the chance to test a Birdy Touring and thus the Shimano Nexave C530 (Intego) 3x8 which is an "alternative" to the SRAM dual drive. Intego offers following great properties against the Dual Drive:
* it is MUCH quieter, I feel disturbed by the noise the Dual Drive produces while "free rolling" (huh, you know the TIC TIC TIC ^^)
* it has Trigger Shifters and I can not live without it

The worrying things about Intego is that It is not a widely-spread gear system (I guess support will be difficult) and the hub has 36 holes, which will be difficult to adapt to the kinetic rims.
All that being said, I am like before still hesitating about what I should do. I am thinking of following possibilities:
a/ buy a Speed P8 (Steal Frame) and 1/ Change the twistgrip shifter with an SRAM X9 Trigger Shifter 2/ eventually add a Speed-Drive afterwards.
b/ buy a Speed Pro (Steal Frame, Alu fork, high-end components) and change the rear wheel from Dual Drive to Intego
c/ buy a Veltraum F2 (Alu Frame) with Speed-drive (approximatively 1500 euros!)

a) is the cheap variant
b) and c) are the "light weight" variants

Why does it have to be that hard to choose a bike ! ;)
Well, that's it, I am out.

Best regards
Valéry.

pismocycleguy 10-10-07 08:10 PM

Sounds as if you will have to purchase more than one bike!!!
Lots of luck!
PCG

Dahon.Steve 10-10-07 08:22 PM

Sounds like you should just get a Bike Friday. All these changes should come cost just about as much as a Friday. As for the noise, this is to be expected since the Sram Spectro 3 was never quite. You just get used to it.

Leigh_caines 10-10-07 10:45 PM

>>The only thing I do not feel confortable with is the SRAM dual drive: apart from the fact that I found it little bit noisy<<

I wonder why? You found it noisy... sounds like something wrong with it...
I've had one on my folding recumbent for 14000ks so far and there is no noisy and they have been rough ks over all sort of rough stuff. [and my one was bought second hand so who knows how many it did before me]
Or maybe mine has so much sh.. in it that it deadens the noise :)


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